genwqe_user_vmap(9)

✨ genwqe_user_vmap ✨

Okay bestie, gather ‘round, because we’re looking at genwqe_user_vmap from the genwqe section 9 kernel API manual 💅 this is the whole vibe, no cap.

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🌸 NAME 🌸

genwqe_user_vmap — Map user-space memory to virtual kernel memory 🫶

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🎀 SYNOPSIS 🎀

int genwqe_user_vmap (struct genwqe_dev *cd , struct dma_mapping *m ,
void *uaddr , unsigned long size );

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💖 ARGUMENTS 💖

• cd — pointer to genwqe device, okay so this is your main character struct 👑
• m — mapping params, literally the mapping details bestie 📋
• uaddr — user virtual address, the address from user space ✨
• size — size of memory to be mapped, how much we’re mapping fr fr 📏

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🦋 DESCRIPTION 🦋

We need to think about how we could speed this up. Of course it is not a good idea to do this over and over again, like we are currently doing it. Nevertheless, I am curious where on the path the performance is spend. Most probably within the memory allocation functions, but maybe also in the DMA mapping code. 👀

Restrictions: The maximum size of the possible mapping currently depends on the amount of memory we can get using kzalloc for the page_list and pci_alloc_consistent for the sg_list. The sg_list is currently itself not scattered, which could be fixed with some effort. The page_list must be split into PAGE_SIZE chunks too. All that will make the complicated code more complicated. 😭

So like, it’s giving “we know this is messy but here we are” energy. The restrictions are real and you gotta respect them — don’t come for this code unless you’re ready for the complications, periodt. 💅

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🔥 RETURN 🔥

0 if success — slay, that’s the good ending ✅

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🌈 SEE ALSO 🌈

Kernel file ./drivers/misc/genwqe/card_utils.c — and bestie, there are so many related functions, iykyk:

__genwqe_writeq(9), __genwqe_readq(9), __genwqe_writel(9), __genwqe_readl(9),
genwqe_read_app_id(9), genwqe_init_crc32(9), genwqe_crc32(9),
genwqe_free_sync_sgl(9), genwqe_user_vunmap(9), genwqe_card_type(9),
genwqe_card_reset(9), genwqe_set_interrupt_capability(9),
genwqe_reset_interrupt_capability(9), set_reg_idx(9),
genwqe_ffdc_buff_size(9), genwqe_ffdc_buff_read(9),
genwqe_write_vreg(9), genwqe_read_vreg(9),
genwqe_base_clock_frequency(9), genwqe_stop_traps(9),
genwqe_start_traps(9)

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That’s the whole page, bestie — source is ./drivers/misc/genwqe, dated October 2026, and this is genwqe_user_vmap(9) signing off 💜✨ stay iconic and map responsibly 🎀